The National Security Agency building in San Antonio is seen in this Thursday June 14, 2013 aerial photo. The NSA may have invested as much as $300 million to overhaul the former Sony fabrication plant, which was closed in 2003, to turn it into a hub of classified activity, However, the agency appears to have departed from its normal process of identifying major construction projects in the Defense Department budget with the San Antonio facility.

The National Security Agency building in San Antonio is seen in...

Over the past six years, the National Security Agency has quietly transformed the former Sony chip fabrication plant on the Northwest Side into a black-box hub of intelligence gathering and data storage.

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